早上好。
我编写了在单线程模式下运行的代码，并尝试将其改编为多线程模式。 我正在单线程模式下运行与MARCH :: RUN_PAR十分相似的方法，但效果很好，但是当我尝试在多线程模式下（使用Openmp）执行时，结果太奇怪了。
有人可以帮助我解决这个问题吗？
下面是我的代码：
void MI_MARCH::RUN_PARALELO(double zt,double ***Vpar,int mt,int red_yred,int prof,int tam) {
int RANK, numero_proc_parall;
int shift,cont,m,rredy;
//start the number of (possible) threads
numero_proc_parall = tam;
//shift the loop of threads
shift = 0;
//the necessary total number of threads
cont = prof;
//set the number of threads
omp_set_num_threads(numero_proc_parall);
//argument initialization
rredy = red_yred;
MARCH VETOR_MARCH[numero_proc_parall]; //vector of class
//open the parallel section
#pragma omp parallel shared(cont,shift,numero_proc_parall) private(red_yred,RANK,m)
{
while(cont > 0)
{
#pragma omp critical
std::cout<<"[MI_MARCH RUN_PAR] loop cont "<<cont<<" shift "<<shift<<" numero_proc_parall "<<numero_proc_parall<<"\n";
#pragma omp for
for(m=0;m<numero_proc_parall;m++) //loop de profundidade
{
//atualize the rank
RANK = omp_get_thread_num();
//set the reference
red_yred = rredy + m + shift
//run the method of the MARCH class
VETOR_MARCH[m].RUN_PAR(zt,Vpar[m],mt,red_yred,RANK + shift);
}
//execute only in the master thread
#pragma omp master
{
//increment the shift variable
shift = shift + numero_proc_parall;
//decrement the loop control
cont = cont - numero_proc_parall;
//verify if the process is greater than controller
if(cont<numero_proc_parall)
{
//set a new number of parallel process
numero_proc_parall = cont;
}
}
#pragma omp barrier //waiting other process
}
}
}
MARCH :: RUN_PAR方法为：
void MARCH::RUN_PAR(double zt,double **Vxy,int mt,int red_yred,int RANK);
{
int xf,yf;
xf = 100;
yf = 100;
//execute this piece of code in critical mode
#pragma omp critical
{
for(int i=0;i<xf;i++)
{
for(int j=0;j<yf;j++)
{
Vcopia[i][j] = Vxy[i][j]; //Vcopia is a member of MARCH class
}
}
}
V_H(Vcopia,xf,yf,red_yred); //this method is a member of MARCH class
CALC(mt,zt,RANK); //this method is a member of MARCH class
}
...
class MARCH{
public:
...
void RUN_PAR(double zt,double **Vxy,int mt,int red_yred,int RANK);
private:
...
double **Vcopia;
...
void V_H(double **Vcopia,int xf,int yf,int red_yred);
void CALC(int mt,double zt,int RANK);
};
不正确的结果显然是在顺序模式下出现的。
单线程模式下的正确结果是这样的图像：correct image
错误使用多个线程是这样的图像：incorrect image
